[R] Odp: Programming: loop versus vector oriented

[Jan private]

Hello Petr,

thank you for your ideas. The split() looks most realistic. 

What about this idea:

1. Define three functions Refun1, Refun2, Refun3 for the three different
sections of the calculations (same as you suggested)
2. lambda = (Re <= 2320) * Refun1(Re)  + ((Re > 2320) && (Re < 65 * dk))
* Refun2(Re) etc.

But my thought is that probably the values of RefunXYZ will be
calculated for every value of Re, even if the condition (Re <= 2320) is
FALSE (= 0). So that would give a lot of unnecessary function
evaluations.

Regards,
	Jan